Using a polymer material such as a dielectric elastomer, development has advanced for small, light-weight transducers having a high degree of flexibility. Examples of a transducer include an actuator in which a pair of electrodes is disposed on both a front and back surface of a dielectric film made from an elastomer (see, for example, Patent Documents 1 and 2). In an actuator of this type, when the applied voltage between the electrodes is increased, an electrostatic attraction between the electrodes increases. Therefore, the dielectric film sandwiched between the electrodes is compressed in a thickness direction and the thickness of the dielectric film decreases. When the film thickness decreases, the dielectric film proportionally extends in a horizontal direction with respect to the electrode surfaces. Meanwhile, when the applied voltage between the electrodes is reduced, the electrostatic attraction between the electrodes decreases. Therefore, the compressive force on the dielectric film in the thickness direction is reduced, and the film thickness increases due to an elastic restorative force of the dielectric film. When the film thickness increases, the dielectric film proportionally contracts in the horizontal direction with respect to the electrode surfaces. In this way, the actuator drives drive target members by extension and contraction of the dielectric film in response to the magnitude of the applied voltage.
In the actuator, the electrodes are affixed to both the front and back surfaces of the dielectric film. Accordingly, the electrodes must be extendable and contractible in response to deformation of the dielectric film so as not to interfere with the extension and contraction thereof.